This invention relates to a method and apparatus for mounting components and more particularly to an improved method and apparatus for moving components from a feed area and appropriately positioning the components at a mounting area.
In many types of assembly apparatus, it is desirable to pick up a component from a delivery station, move it to a mounting station and mount it on a substrate such as a printed circuit board or the like. With such apparatus, it is desirable that the apparatus can move at a high rate of speed in order to produce the requisite assemblies at a low cost. The time during which the component is transported from its picked up location to its deposited location is, in effect, lost time with most apparatus.
It is, therefore, a principal object of this invention to provide an improved method and apparatus for moving components between one location and another and performing an operation on the components when they are being transported.
By way of example, a wide variety of apparatus have been proposed for picking up small components such as IC's, resistors, condensers or the like and positioning them for mounting on a substrate such as a printed circuit board or the like. In order to permit accurate mounting of the component, the orientation of the component relative to the pick up device once it is picked up must be determined. Normally the components are presented to the pick up device at a station and frequently the components are mounted in recesses on a tape or the like. As such, it is not accurately known what the position of the component is relative to the pick up device when the component is picked up.
Thus, considering the "X","Y" axes and the rotational position .theta. about the axis of the pick up device, it is necessary to measure the correction factors both in the "X" direction, in the "Y" direction and the rotational position of the component relative to the pick up device when the component is picked up. Various measuring devices have been proposed for this purpose.
The disadvantage of necessitating separate measurements is that the measurements all take time and, therefore, the previously proposed devices have been relatively slow in operation.
It is, therefore, a principal object to this invention to provide an improved method and apparatus for determining the correction necessary for a component that is picked up by a gripping device so that it can be accurately positioned.
It is a further object to this invention to provide an improved method and apparatus for determining the position of a component that is picked up by a pick up device.
It is yet a further object to this invention to provide an improved method and apparatus for determining the correction necessary for a component during the time period when the component is being transported between its picked up location and its deposited location.
Devices of the type previously described have generally been configured so as to handle only a single component at a given time. However, the device can be much more expeditiously constructed and operated if a plurality of components may be transported simultaneously. Although this simultaneous transportation is desirable, it is also desirable if certain processes can be performed on the components when they are being transported and this can give rise to difficulties in that there may be interference between the respective components during the time period when they are being transported.
It is, therefore, a still further object to this invention to provide an improved apparatus for transporting a plurality of picked up components and performing an operation on all of those components during the time when they are transported.
For example, it has already been noted that it is desirable to provide a mechanism for sensing the orientation of the components. Quite advantageously, this can be done during the time when the components are being transported. However, if a sensing device is employed it is desirable to insure that all transported components may be sensed at the same time or during the same movement.
It is, therefore, a still further object to this invention to provide an improved component handling device wherein a sensing arrangement is provided that is adapted to sense the condition of a plurality of components all being transported at the same time.
When a device is provided for accommodating the sensing of a plurality of objects during their transportation and the sensing device is of the optical type, it is desirable to insure that there is an offset between the components and the sensing device so that each component can be sensed without interference from the others. This offsetting can be accomplished by either staggering the pick up device and/or the sensing device. However, when this staggering is done then the pick up devices may be located or oriented in such a way that they cannot pick up or deposit articles simultaneously. This can considerably slow down the operation.
It is, therefore, a still further object to this invention to provide an improved article handling device wherein a plurality of components may be sensed during their transportation and yet the pick up devices and the feeders for them are oriented so as to permit simultaneous pick up and or delivery.